A terminal olefin-containing dioxane liquid crystal compound, a preparation method and application thereof

Abstract

This invention relates to a terminal alkenyl dioxane-containing liquid crystal compound, its preparation method, and its application. The compound has a structure as shown in Formula I, wherein R is selected from fluorine, C1-C12 alkyl, fluorinated C1-C12 alkyl, C1-C12 alkoxy, fluorinated C1-C12 alkoxy, C2-C12 alkenyl, C2-C12 alkenyl, fluorinated C2-C6 alkenyl, or fluorinated C2-C6 alkenyl. The compound prepared in this application has a large response speed, a large refractive index, and a clearing point, as well as a wide phase transition temperature. Furthermore, the synthesis route is short, the raw material cost is low, and the post-processing is simple, making it suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of organic materials technology, and relates to a liquid crystal compound containing terminal alkenyl dioxane, its preparation method and application. Background Technology

[0002] With the rapid development of information technology, display technology has become an indispensable part of people's daily life, work, and many industries. Liquid Crystal Display (LCD) technology boasts numerous advantages, including its thinness, low power consumption, ease of mass production, and ability to achieve high-quality image display. In LCD devices, liquid crystal material serves as the core component, and its performance plays a decisive role in the overall display effect, directly affecting key indicators such as image clarity, contrast, response speed, and stability under different ambient temperatures.

[0003] The refractive index of a liquid crystal compound affects the refraction and reflection of light as it propagates within it, thus determining the brightness, color saturation, and other visual effects of a display device. However, many current traditional liquid crystal compounds have relatively limited refractive indices, resulting in insufficient light utilization efficiency and difficulty in achieving high brightness and vibrant colors. Liquid crystal molecules need to change their alignment under an applied electric field to switch and display images; however, some existing liquid crystal compounds have slow response times, easily causing ghosting when displaying dynamic images (such as fast-paced videos and high frame rate games), severely impacting the smoothness of the visual experience.

[0004] Given the shortcomings of existing liquid crystal compounds in key performance aspects such as refractive index and response speed, and the urgent need for high-performance liquid crystal materials in modern display technology, there is an urgent need to provide a liquid crystal compound with higher refractive index and response speed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a liquid crystal compound containing terminal alkenyl dioxane, its preparation method, and its applications.

[0006] To achieve this objective, the present invention employs the following technical solution:

[0007] In a first aspect, the present invention provides a liquid crystal compound containing terminal alkenyl dioxane, said compound having a structure as shown in Formula I:

[0008]

[0009] The R is selected from fluorine, C1-C12 alkyl, fluorinated C1-C12 alkyl, C1-C12 alkoxy, fluorinated C1-C12 alkoxy, C2-C12 alkenyl, C2-C12 alkenyl, fluorinated C2-C6 alkenyl, or fluorinated C2-C6 alkenyl, but not limited to fluorine.

[0010] Ring A is selected from methyl-substituted, nitrogen-substituted, or unsubstituted rings. Any one of them.

[0011] Preferably, the structure of the compound is selected from any one of the following structures:

[0012]

[0013] Preferably, the compound is selected from any one of the following:

[0014]

[0015]

[0016] Secondly, the present invention provides a method for preparing a liquid crystal compound containing terminal alkene dioxane, the method comprising:

[0017] (1) React the compound shown in Formula II with the compound shown in Formula III to obtain the compound shown in Formula IV;

[0018]

[0019] (2) React the compound shown in Formula IV with the compound shown in Formula V to obtain the compound shown in Formula I;

[0020]

[0021] Where X is selected from hydrogen, bromine, or iodine.

[0022] Preferably, in step (1), the molar ratio of the compound represented by formula II to the compound represented by formula III is (0.9-1.1):1, where the specific point values ​​in (0.9-1.1) can be selected from 0.9, 0.92, 0.94, 0.96, 0.98, 1, 1.02, 1.04, 1.06, 1.08, 1.1, etc. Other specific point values ​​within the above range can be selected, and will not be elaborated here.

[0023] Preferably, step (1) is carried out under the conditions of a first organic solvent and a dehydrating agent.

[0024] Preferably, the molar ratio of the compound represented by Formula III, the first organic solvent, and the dehydrating agent is 1:(3-20):(0.05-1), and more preferably 1:(3-10):(0.05-0.2).

[0025] The specific point values ​​in (3-20) can all be selected from 3, 5, 8, 10, 12, 14, 16, 18, 20, etc.; the specific point values ​​in (0.05-1) can all be selected from 0.05, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.; the specific point values ​​in (3-10) can all be selected from 3, 4, 5, 6, 7, 8, 9, 10, etc. Other specific point values ​​within the above range can also be selected, which will not be elaborated here.

[0026] Preferably, the molar ratio of the compound represented by Formula II, the compound represented by Formula III, the first organic solvent, and the dehydrating agent is (0.9-1.1):1:(3-10):(0.05-0.2).

[0027] The specific point values ​​in (0.9-1.1) can be selected from 0.9, 0.92, 0.94, 0.96, 0.98, 1, 1.02, 1.04, 1.06, 1.08, 1.1, etc.; the specific point values ​​in (3-10) can be selected from 3, 4, 5, 6, 7, 8, 9, 10, etc.; the specific point values ​​in (0.05-0.2) can be selected from 0.05, 0.08, 0.1, 0.12, 0.15, 0.18, 0.2, etc.; other specific point values ​​within the above range can also be selected, which will not be elaborated here.

[0028] Preferably, the first organic solvent in step (1) includes any one or a combination of at least two of dichloromethane, dichloroethane, petroleum ether, n-heptane, toluene, or xylene, and more preferably any one or a combination of at least two of dichloromethane, petroleum ether, n-heptane, or toluene.

[0029] Preferably, the dehydrating agent comprises any one or a combination of at least two of p-toluenesulfonic acid, p-toluenesulfonic acid pyridinium salt, or a chloride saturated solution of hydrochloric acid, more preferably p-toluenesulfonic acid and / or p-toluenesulfonic acid pyridinium salt.

[0030] Preferably, the reaction temperature in step (1) is 40-110℃ and the reaction time is 0.5-24h.

[0031] Temperatures can be selected from 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, etc., and time can be selected from 0.5h, 1h, 2h, 5h, 8h, 0h, 12h, 5h, 18h, 20h, 22h, 24h, etc. Other specific point values ​​within the above range can be selected, which will not be elaborated here.

[0032] Preferably, step (2) specifically includes: reacting the compound shown in formula IV with the compound shown in formula V under the condition of a second organic solvent to obtain a reaction solution; reacting the reaction solution under the condition of a first organic solvent and a dehydrating agent to obtain the compound shown in formula I.

[0033] Preferably, the molar ratio of the compound shown in Formula IV to the compound shown in Formula V is (0.8-2):1, more preferably (0.9-1.2):1.

[0034] The specific point values ​​in (0.8-2) can be selected from 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, etc. Other specific point values ​​within the above range can also be selected, which will not be elaborated here.

[0035] Preferably, the ratio of the reaction solution, the first organic solvent, and the dehydrating agent is 1:(3-20):(0.05-1), and more preferably 1:(3-10):(0.05-0.2).

[0036] The specific point values ​​in (3-20) can all be selected from 3, 5, 8, 10, 12, 14, 16, 18, 20, etc.; the specific point values ​​in (0.05-1) can all be selected from 0.05, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.; the specific point values ​​in (3-10) can all be selected from 3, 4, 5, 6, 7, 8, 9, 10, etc. Other specific point values ​​within the above range can also be selected, which will not be elaborated here.

[0037] Preferably, the second organic solvent includes any one or a combination of at least two of diethyl ether, tetrahydrofuran, or 2-methyltetrahydrofuran.

[0038] Preferably, the molar ratio of the compound shown in Formula IV, the compound shown in Formula V, and the second organic solvent is (0.9-1.2):1:(3-10).

[0039] The specific point values ​​in (0.9-1.2) can be selected from 0.9, 0.95, 1, 1.05, 1.1, 1.15, 1.2, etc., and the specific point values ​​in (3-10) can be selected from 3, 4, 5, 6, 7, 8, 9, 10, etc. Other specific point values ​​within the above range can be selected, which will not be elaborated here.

[0040] Preferably, step (2) is carried out under alkaline conditions.

[0041] Preferably, the alkali is selected from any one or a combination of at least two of n-butyllithium, sec-butyllithium, tert-butyllithium, isopropyl magnesium chloride, isopropyl magnesium chloride, lithium chloride, or diisopropylaminolithium.

[0042] Preferably, the reaction is carried out in a second organic solvent at a temperature of -100 to 20°C for a time of 0.5 to 24 hours.

[0043] Temperatures can be selected from -100℃, -90℃, -80℃, -70℃, -60℃, -50℃, -40℃, -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, etc. Time can be selected from 0.5h, 1h, 2h, 5h, 8h, 0h, 12h, 5h, 18h, 20h, 22h, 24h, etc. Other specific point values ​​within the above range can be selected, which will not be elaborated here.

[0044] Preferably, in step (2), the reaction temperature is 20-110°C and the time is 0.5-24h in the presence of the first organic solvent and the dehydrating agent.

[0045] Temperatures can be selected from 20℃, 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, etc., and time can be selected from 0.5h, 1h, 2h, 5h, 8h, 0h, 12h, 5h, 18h, 20h, 22h, 24h, etc. Other specific values ​​within the above ranges can also be selected, which will not be elaborated here.

[0046] Thirdly, the present invention provides a liquid crystal composition comprising the terminal alkene dioxane-containing liquid crystal compound described in the first aspect.

[0047] Preferably, the terminal alkenyl dioxane-containing liquid crystal compound accounts for 0.1%-30% of the weight percentage of the liquid crystal composition, such as 0.1%, 0.5%, 1%, 5%, 10%, 20%, 25%, 30%, etc. Other specific values ​​within the above range can be selected, and will not be elaborated here.

[0048] Preferably, the liquid crystal composition further includes at least one compound of general formula M, at least one compound of general formula A1, and at least one compound of general formula A2;

[0049]

[0050] Among them, R M1 and R M2 Each can independently represent -H, a straight-chain or branched alkyl group containing 1-12 carbon atoms, One or more non-adjacent -CH2- atoms in the straight-chain or branched alkyl group containing 1-12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, or -O-CO-.

[0051] R A1 and R A2 Each independently represents a straight-chain or branched alkyl group containing 1-12 carbon atoms. One or more non-adjacent -CH2- atoms in the straight-chain or branched alkyl group containing 1-12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, or -O-CO-, and the straight-chain or branched alkyl group containing 1-12 carbon atoms... One or at least two -H can be independently replaced by -F or -Cl;

[0052] Z M1 and Z M2 Each can independently represent a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2-, or -(CH2)4-;

[0053] Z A11 Z A21 and Z A22 Each can independently represent a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH2O-, or -OCH2-;

[0054] L A11 L A12 L A13 L A21 and L A22 Each can independently represent -H, an alkyl group containing 1-3 carbon atoms, or a halogen;

[0055] X A1 and X A2Each can independently represent a halogen, a haloalkyl or haloalkoxy group containing 1-5 carbon atoms, or a haloalkenyl or haloalkenoxy group containing 2-5 carbon atoms.

[0056] ring ring and ring Each represents independently in, At least two of the -CH2- can be replaced by -O-. At most one -H in the halogen can be replaced by a halogen;

[0057] ring ring ring and ring Each represents independently in, One or more of the -CH2- bonds can be replaced by -O- bonds, and one or more single bonds in a ring can be replaced by double bonds. One or more of the -H can be replaced by -CN, -F or -Cl, and -CH= in one or more of the rings can be replaced by -N=;

[0058] n M1 n A11 and n A2 Each can independently represent 0, 1, 2, or 3, and when n M1 When = 2 or 3, the ring They can be the same or different, Z M2 They can be the same or different; when n A11 When = 2 or 3, the ring They can be the same or different, Z A11 They can be the same or different; when n A2 When = 2 or 3, the ring They can be the same or different, Z A21 They can be the same or different;

[0059] n A12 Represents 1 or 2, and when n A12 When = 2, ring They can be the same or different.

[0060] Preferably, the compound of general formula M is selected from the following compounds:

[0061]

[0062]

[0063] Preferably, the compound of general formula M accounts for 0.1%-90% of the weight percentage of the liquid crystal composition, for example, 0.1%, 0.5%, 1%, 5%, 10%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%.

[0064] In some embodiments of the present invention, the content of the compound of general formula M must be appropriately adjusted according to the required properties such as solubility at low temperature, transition temperature, electrical reliability, birefringence, process adaptability, drip marks, burn-in, and dielectric anisotropy.

[0065] Regarding the weight percentage of the compound of general formula M in the liquid crystal composition of the present invention, the preferred lower limit is 0.1%, 1%, 10%, 20%, 30%, 40%, or 50% relative to the total weight of the liquid crystal composition of the present invention; the preferred upper limit is 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 35%, or 25% relative to the total weight of the liquid crystal composition of the present invention.

[0066] Regarding the content of compounds of general formula M, when it is necessary to maintain a low viscosity and a short response time in the liquid crystal composition of the present invention, it is preferable to have a higher lower limit and a higher upper limit; further, when it is necessary to maintain a high clearing point and good temperature stability in the liquid crystal composition of the present invention, it is preferable to have a higher lower limit and a higher upper limit; in order to keep the driving voltage low and increase the absolute value of dielectric anisotropy, it is preferable to have a lower lower limit and a lower upper limit.

[0067] In some embodiments of the present invention, when reliability is of priority, it is preferred that RM1 and RM2 are both alkyl; when reducing the volatility of the compound is of priority, it is preferred that RM1 and RM2 are both alkoxy; when reducing viscosity is of priority, it is preferred that at least one of RM1 and RM2 is alkenyl.

[0068] In some embodiments of the invention, the compound of general formula M is preferably free from the group consisting of compounds of general formulas M1, M2, M3, M4, M5, M7, M8, M9, M10, M11, M13, M15, M16, M17, M18, M19, M20, M21, M22, M23 and M24.

[0069] In some embodiments of the invention, compounds of general formula M are further preferably the group consisting of compounds of general formulas M1, M2, M4, M5, M9, M11, M13, M20 and M22.

[0070] In some embodiments of the present invention, in compounds of general formula M1, RM1 represents a straight-chain or branched alkyl or alkoxy group containing 1 to 7 carbon atoms; more preferably, a straight-chain or branched alkyl or alkoxy group containing 1 to 5 carbon atoms.

[0071] Preferred weight percentages of the compound of general formula M1 in the liquid crystal composition of the present invention: the preferred lower limit of the weight percentage of the compound of general formula M1 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 1%, 3%, 5%, 7%, 10%, 13%, 15%, 17%, 20%, 23%, 25%, or 30%; the preferred upper limit of the weight percentage of the compound of general formula M1 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 60%, 55%, 50%, 45%, 40%, 37%, 35%, 33%, 30%, 27%, 25%, 23%, 20%, 17%, 15%, 13%, or 10%.

[0072] To particularly improve the response time of the liquid crystal composition of the present invention, it is preferred that the compound of general formula M1 has RM1 as ethyl, n-propyl, butyl, or pentyl and RM2 as methyl or methoxy, the compound of general formula M1 has RM1 as ethyl, n-propyl, butyl, or pentyl and RM2 as ethyl or ethoxy, or the compound of general formula M1 has RM1 as n-propyl, butyl, or pentyl and RM2 as n-propyl or propoxy.

[0073] The preferred lower limit of the weight percentage of the compound of general formula M1 in which RM1 is n-propyl and RM2 is ethyl relative to the total weight of the liquid crystal composition of the present invention is 1%, 2%, 3%, 5%, 7%, 10%, 13%, 15%, 18% or 20%; the preferred upper limit of the weight percentage of the compound of general formula M1 in which RM1 is n-propyl and RM2 is ethyl relative to the total weight of the liquid crystal composition of the present invention is 20%, 17%, 15%, 13%, 10%, 8%, 7% or 6%.

[0074] The preferred weight percentage of the compound of general formula M2 in the liquid crystal composition of the present invention is as follows: the lower limit of the weight percentage of the compound of general formula M2 in the liquid crystal composition of the present invention is 1%, 2%, 3%, 5%, 7% or 10% relative to the total weight of the liquid crystal composition of the present invention; the upper limit of the weight percentage of the compound of general formula M2 in the liquid crystal composition of the present invention is 20%, 15%, 13%, 10%, 8%, 7%, 6%, 5% or 3% relative to the total weight of the liquid crystal composition of the present invention.

[0075] The preferred weight percentage of the compound of general formula M4 in the liquid crystal composition of the present invention is as follows: the lower limit of the weight percentage of the compound of general formula M4 in the liquid crystal composition of the present invention is 1%, 2%, 3%, 5%, 7% or 10% relative to the total weight of the liquid crystal composition of the present invention; the upper limit of the weight percentage of the compound of general formula M4 in the liquid crystal composition of the present invention is 20%, 15%, 13%, 10%, 8%, 7%, 6%, 5% or 3% relative to the total weight of the liquid crystal composition of the present invention.

[0076] Regarding the preferred weight percentage of the compound of general formula M9 in the liquid crystal composition of the present invention: the preferred lower limit of the weight percentage of the compound of general formula M9 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 1%, 2%, 3%, 5%, 7%, 10%, 14%, 16%, 20%, 23%, 26%, 30%, 35%, or 40%; the preferred upper limit of the weight percentage of the compound of general formula M9 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 50%, 40%, 35%, 30%, 20%, 15%, 10%, or 5%.

[0077] In some embodiments of the present invention, depending on the required properties such as solubility at low temperatures, transition temperature, electrical reliability, and birefringence, it is preferable to use compounds containing the general formula M9 in which RM1 is a straight-chain or branched alkenyl group containing 2-4 carbon atoms and RM2 is CH3-. The straight-chain or branched alkenyl group containing 2-4 carbon atoms is further preferably...

[0078] Relative to the total weight of the liquid crystal composition of the present invention, RM1 in the compound of general formula M9 is The preferred lower limit of the weight percentage of the compound RM2 being CH3- in the liquid crystal composition of the present invention is 1%, 3%, 5%, 7%, 9%, 11%, 12%, 13%, 18%, or 21%, and the preferred upper limit is 45%, 40%, 35%, 30%, 25%, 23%, 20%, 18%, 15%, 13%, 10%, or 8%. When both compounds are present, the preferred lower limit of the weight percentage of the two compounds relative to the total weight of the liquid crystal composition of the present invention is 3%, 5%, 7%, 9%, 11%, 13%, 15%, 19%, 24%, or 30%, and the preferred upper limit is 45%, 40%, 35%, 30%, 25%, 23%, 20%, 18%, 15%, 13%, 11%, or 9%.

[0079] The preferred weight percentage of the compound of general formula M10 in the liquid crystal composition of the present invention is as follows: the lower limit of the weight percentage of the compound of general formula M10 in the liquid crystal composition of the present invention is 1%, 2%, 3%, 4%, 5%, 7%, 10%, 14%, 16% or 20% relative to the total weight of the liquid crystal composition of the present invention; the upper limit of the weight percentage of the compound of general formula M10 in the liquid crystal composition of the present invention is 45%, 40%, 35%, 30%, 20%, 15%, 10% or 5% relative to the total weight of the liquid crystal composition of the present invention.

[0080] In some embodiments of the present invention, depending on the required properties such as solubility at low temperatures, transition temperature, electrical reliability, and birefringence, it is preferable to use compounds containing the general formula M10 in which RM1 is a straight-chain or branched alkenyl group containing 2-4 carbon atoms and RM2 is CH3-. The straight-chain or branched alkenyl group containing 2-4 carbon atoms is further preferably...

[0081] Relative to the total weight of the liquid crystal composition of the present invention, RM1 in the compound of general formula M10 is The preferred lower limit of the weight percentage of the compound RM2 being CH3- in the liquid crystal composition of the present invention is 1%, 3%, 4%, 5%, 7%, 9%, 11%, 12%, 13%, 18%, or 20%, and the preferred upper limit is 40%, 35%, 30%, 25%, 23%, 20%, 18%, 15%, 13%, 10%, or 8%. When both compounds are present, the preferred lower limit of the weight percentage of the two compounds in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 3%, 5%, 7%, 9%, 11%, 13%, 15%, 19%, 24%, or 30%, and the preferred upper limit is 45%, 40%, 35%, 30%, 25%, 23%, 20%, 18%, 15%, or 13%.

[0082] Regarding the preferred weight percentage of the compound of general formula M11 in the liquid crystal composition of the present invention: the preferred lower limit of the weight percentage of the compound of general formula M11 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 1%, 2%, 3%, 5%, 7%, 10%, 14%, 16%, 20%, 23%, 26%, 30%, 35%, or 40%; the preferred upper limit of the weight percentage of the compound of general formula M11 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 50%, 40%, 35%, 30%, 20%, 15%, 10%, or 5%.

[0083] In some embodiments of the present invention, the compound of general formula M11 is preferably a compound in which RM1 is n-propyl or n-pentyl and RM2 is C2H5-, or preferably RM1 is... The compound in which RM2 is n-propyl, or preferably RM1 is n-propyl, n-butyl or n-pentyl and RM2 is CH3O-; particularly preferred are compounds in which RM1 is n-propyl and RM2 is C2H5-.

[0084] Regarding the preferred weight percentage of the compound of general formula M13 in the liquid crystal composition of the present invention: the preferred lower limit of the weight percentage of the compound of general formula M13 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 1%, 2%, 3%, 5%, 7%, 10%, 14%, 16%, 20%, 23%, 26%, 30%, 35%, or 40%; the preferred upper limit of the weight percentage of the compound of general formula M13 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 50%, 40%, 35%, 30%, 20%, 15%, 10%, or 5%.

[0085] In some embodiments of the present invention, compounds of general formula M13 preferably have RM1 and RM2 each independently representing straight-chain or branched alkyl compounds containing 2-5 carbon atoms, or preferably one of RM1 and RM2 is... The other is a compound of CH3- or C2H5-.

[0086] Regarding the preferred weight percentage of the compound of general formula M15 in the liquid crystal composition of the present invention: the preferred lower limit value of the weight percentage of the compound of general formula M15 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 1%, 2%, 3%, 5%, 7%, 10%, 12%, 14%, 16%, 18%, 20%, 23%, 26%, 30%, 35%, or 40%; the preferred upper limit value of the weight percentage of the compound of general formula M15 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 50%, 40%, 35%, 30%, 25%, 22%, 20%, 18%, 15%, 12%, 10%, 8%, or 5%.

[0087] Regarding the preferred weight percentage of the compound of general formula M16 in the liquid crystal composition of the present invention: the preferred lower limit of the weight percentage of the compound of general formula M16 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 1%, 2%, 3%, 5%, 7%, 10%, 12%, 14%, 16%, 18%, 20%, 23%, 26%, 30%, 35%, or 40%; the preferred upper limit of the weight percentage of the compound of general formula M16 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 50%, 40%, 35%, 30%, 25%, 22%, 20%, 18%, 15%, 12%, 10%, 8%, or 5%.

[0088] Regarding the weight percentage of compounds of general formulas M20 to M24 in the liquid crystal composition of the present invention, the preferred lower limit values ​​are 1%, 2%, 3%, 5%, 7%, 10%, 14%, 16%, or 20% relative to the total weight of the liquid crystal composition of the present invention; and the preferred upper limit values ​​are 30%, 25%, 23%, 20%, 18%, 15%, 12%, 10%, or 5% relative to the total weight of the liquid crystal composition of the present invention.

[0089] In some embodiments of the present invention, the compound of general formula A-1 is selected from the following compounds:

[0090]

[0091]

[0092]

[0093] Wherein, RA1 represents a straight-chain or branched alkyl group containing 1-8 carbon atoms. One or more non-adjacent -CH2- groups in the straight-chain or branched alkyl groups containing 1-8 carbon atoms may be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H groups present in these groups may be independently replaced by -F or -Cl.

[0094] Rv and Rw each independently represent -CH2- or -O-;

[0095] LA11, LA12, LA11', LA12', LA14, LA15, and LA16 each independently represent -H or -F;

[0096] LA13 and LA13' each independently represent -H or -CH3;

[0097] XA1 represents -F, -CF3, or -OCF3; and

[0098] v and w each represent 0 or 1 independently.

[0099] In some embodiments of the present invention, the compound of general formula A-1 accounts for 0.1%-80% by weight of the liquid crystal composition, for example 0.1%, 0.5%, 1%, 5%, 10%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or 80%.

[0100] Regarding the preferred weight percentage of the compound of general formula A-1 in the liquid crystal composition of the present invention: the preferred lower limit value of the weight percentage of the compound of general formula A-1 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 15%, 17%, 18% or 20%; the preferred upper limit value of the weight percentage of the compound of general formula A-1 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30% or 25%.

[0101] Regarding the preferred content of the compound of general formula A-1, in order to keep the viscosity of the liquid crystal composition of the present invention low and the response speed fast, it is preferable to keep the lower limit value slightly low and the upper limit value slightly low; furthermore, in order to keep the clearing point of the liquid crystal composition of the present invention high and the temperature stability good, it is preferable to keep the lower limit value slightly low and the upper limit value slightly low; in addition, in order to keep the driving voltage low and to increase the absolute value of dielectric anisotropy, it is preferable to keep the lower limit value slightly high and the upper limit value slightly high.

[0102] In some embodiments of the present invention, the compound of general formula A-1 is preferably selected from the group consisting of compounds of general formula A-1-1, general formula A-1-4, general formula A-1-7, general formula A-1-13, general formula A-1-14, general formula A-1-15, general formula A-1-16 and general formula A-1-17.

[0103] In some embodiments of the invention, the compound of general formula A-1 is further preferably the group consisting of compounds of general formulas A-1-4, A-1-7, A-1-13, A-1-14 and A-1-15.

[0104] In some embodiments of the present invention, the compound of general formula A-2 is selected from the following compounds:

[0105]

[0106]

[0107] Wherein, RA2 represents a straight-chain or branched alkyl group containing 1-8 carbon atoms, wherein one or more non-adjacent -CH2- groups of the straight-chain or branched alkyl group containing 1-8 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O- or -O-CO-, and one or at least two -H groups present in these groups can be independently replaced by -F or -Cl;

[0108] LA21, LA22, LA23, LA24 and LA25 each independently represent -H or -F; and XA2 represents -F, -CF3, -OCF3 or -CH2CH2CH=CF2.

[0109] In some embodiments of the present invention, the compound of general formula A-2 accounts for 0.1%-80% by weight of the liquid crystal composition, for example, 0.1%, 0.5%, 1%, 5%, 10%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80%.

[0110] Regarding the preferred weight percentage of the compound of general formula A-2 in the liquid crystal composition of the present invention: the preferred lower limit value of the weight percentage of the compound of general formula A-2 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 0.1%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 15%, 17%, 18% or 20%; the preferred upper limit value of the weight percentage of the compound of general formula A-2 in the liquid crystal composition of the present invention relative to the total weight of the liquid crystal composition of the present invention is 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30% or 25%.

[0111] Regarding the preferred content of the compound of general formula A-2, in order to keep the viscosity of the liquid crystal composition of the present invention low and the response speed fast, it is preferable to keep the lower limit value slightly low and the upper limit value slightly low; furthermore, in order to keep the clearing point of the liquid crystal composition of the present invention high and the temperature stability good, it is preferable to keep the lower limit value slightly low and the upper limit value slightly low; in addition, in order to keep the driving voltage low and to increase the absolute value of dielectric anisotropy, it is preferable to keep the lower limit value slightly high and the upper limit value slightly high.

[0112] In some embodiments of the present invention, the compound of general formula A-2 is preferably selected from the group consisting of compounds of general formula A-2-4, general formula A-2-8, general formula A-2-11 and general formula A-2-12.

[0113] Preferably, the liquid crystal composition of the present invention further includes any one or a combination of at least two of nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, antioxidants, ultraviolet absorbers, infrared absorbers, polymerizable monomers, or light stabilizers.

[0114] Preferably, the dopants in the liquid crystal composition include:

[0115]

[0116]

[0117] Preferably, the dopant accounts for 0-5% of the weight percentage of the liquid crystal composition, for example, 0%, 0.1%, 0.5%, 1%, 2%, 3%, 4% or 5%; more preferably, the dopant accounts for 0-1% of the weight percentage of the liquid crystal composition.

[0118] Preferably, the antioxidants and light stabilizers used in the liquid crystal composition of the present invention are the following substances:

[0119]

[0120]

[0121]

[0122] Where n represents a positive integer from 1 to 12.

[0123] Preferably, the light stabilizer is selected from the light stabilizers shown below:

[0124]

[0125] Preferably, the light stabilizer accounts for 0-5% of the total weight of the liquid crystal composition, for example, 0%, 0.1%, 0.5%, 1%, 2%, 3%, 4% or 5%; more preferably, the light stabilizer accounts for 0-1% of the total weight of the liquid crystal composition; particularly preferably, the light stabilizer accounts for 0.01-0.1% of the total weight of the liquid crystal composition.

[0126] Fourthly, the present invention provides the use of the terminal alkene dioxane-containing liquid crystal compound according to the first aspect or the liquid crystal composition according to the third aspect in the preparation of a liquid crystal display device.

[0127] Compared with the prior art, the present invention has the following beneficial effects:

[0128] 1. Compound P has a large response speed, a large refractive index and a clearing point, and a wide phase transition temperature.

[0129] 2. The synthesis route is short, the raw material cost is low, and the post-processing is simple, making it suitable for industrial production. Detailed Implementation

[0130] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0131] Example 1

[0132] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkene dioxane, the preparation method comprising:

[0133]

[0134] (1) In a 500 mL three-necked flask, 10.2 g (100 mmol) of compound A-1, 12.6 g (100 mmol) of B-1, and 1.9 g (10 mmol) of p-toluenesulfonic acid were added to 200 mL of dichloromethane. A water separation apparatus was set up, and the mixture was heated to 40 °C and refluxed for 30 min to separate the water. After cooling to room temperature, 150 mL of water was added to the mixture for liquefaction. The aqueous phase was extracted with 2 × 100 mL of dichloromethane, and the organic phases were combined. The mixture was washed with 3 × 80 mL of water, and the solvent was evaporated at 30 °C under negative pressure to obtain 17.8 g of a light yellow oily liquid C-1.

[0135] Compound C-1 has a purity of 92.1% (including cis and trans) and a yield of 84.8%.

[0136] (2) In a 500mL three-necked flask, add 200mL of tetrahydrofuran and 13.4g (85mmol) of compound D-1, purge with nitrogen more than 3 times, cool to about -60℃, add 34mL (85mmol, 2.5M) of n-butyllithium dropwise, keep warm for 1h, add 17.8g (84.8mmol) of tetrahydrofuran solution of compound C-1 dropwise (17.8g C-1 dissolved in 50mL tetrahydrofuran), keep warm at about -60℃ for 2h.

[0137] (3) Dehydration: Naturally heat to -40℃ and add 150mL of saturated ammonium chloride solution. Stir and naturally heat to room temperature. Extract with 3×100mL toluene. Combine the organic phases and wash with 3×100mL of water until neutral. Add 1.6g (8.5mmol) of p-toluenesulfonic acid and react at around 85℃ for 3h.

[0138] (4) Post-treatment: Cool to room temperature, transfer to a separatory funnel, add 3 × 100 mL of water and wash until neutral, concentrate toluene at 70℃ and negative pressure (-0.095 MPa). Spread 15 g of 200-300 mesh silica gel, dissolve the concentrated product in petroleum ether and pass through a column, evaporate the solvent at 50℃ to obtain 28 g of viscous solid. Add toluene:ethanol = 2:4 for recrystallization, freeze at -30℃ for 3 h, filter through a Buchner funnel and dry to obtain 22.5 g of white solid, denoted as P-1.

[0139] Compound P-1 purity: 99.91%; yield: 76%.

[0140] The target product was characterized by mass spectrometry (MS). M+(350): 25(36%), 26(14%), 27(16%), 41(100%), 43(10%), 67(56%), 113(33%), 127(42%), 220(33%), 248(55%), 249(12%), 265(14%), 350(26%).

[0141] Example 2

[0142] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkene dioxane, the preparation method comprising:

[0143]

[0144] (1) In a 500 mL three-necked flask, 10.2 g (100 mmol) of compound A-1, 12.6 g (100 mmol) of B-1, and 1.9 g (10 mmol) of p-toluenesulfonic acid were added to 200 mL of dichloromethane. A water separation apparatus was set up, and the mixture was heated to 40 °C and refluxed for 30 min to separate the water. After cooling to room temperature, 150 mL of water was added to the mixture for liquefaction. The aqueous phase was extracted with 2 × 100 mL of dichloromethane, and the organic phases were combined. The mixture was washed with 3 × 80 mL of water, and the solvent was evaporated at 30 °C under negative pressure to obtain 17.8 g of a light yellow oily liquid C-1.

[0145] Compound C-1 has a purity of 92.1% (including cis and trans) and a yield of 84.8%.

[0146] (2) In a 500 mL three-necked flask, add 150 mL of tetrahydrofuran and 13.4 g (95 mmol) of compound D-3, purge with nitrogen more than 3 times, cool to about -5 °C, and add 47.5 mL (95 mmol, 2.0 M) of tetrahydrofuran solution of magnesium isopropyl chloride dropwise at about -5 °C. Keep warm for 1 h, then add 17.8 g (84.8 mmol) of tetrahydrofuran solution of compound C-1 (17.8 g C-1 dissolved in 50 mL of tetrahydrofuran), and keep warm at about -5 °C for 2 h.

[0147] (3) Dehydration: Naturally heat to -40℃ and add 150mL of saturated ammonium chloride solution. Stir and naturally heat to room temperature. Extract with 3×100mL of dichloromethane. Combine the organic phases and wash with 3×100mL of water until neutral. Add 1.6g (8.5mmol) of p-toluenesulfonic acid and reflux at 40℃ for 1h.

[0148] (4) Post-treatment: Cool to room temperature, transfer to a separatory funnel, add 3×100mL of water to wash until neutral, and concentrate the dry dichloromethane at 30℃ under negative pressure (-0.095MPa). Spread 15g of 200-300 mesh silica gel, dissolve the concentrated product in petroleum ether and pass through a column, evaporate the solvent at 50℃ to obtain 28.2g of viscous solid. Add toluene:ethanol = 2:4 for recrystallization, freeze at -30℃ for 3h, filter through a Buchner funnel and dry to obtain 23g of white solid.

[0149] Compound P-1 purity: 99.93%; yield: 77.8%.

[0150] The target product was characterized by mass spectrometry (MS). M+(350): 25(36%), 26(14%), 27(16%), 41(100%), 43(10%), 67(56%), 113(33%), 127(42%), 220(33%), 248(55%), 249(12%), 265(14%), 350(26%).

[0151] Example 3

[0152] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkene dioxane, the preparation method comprising:

[0153]

[0154] (1) In a 500 mL three-necked flask, 10.2 g (100 mmol) of compound A-1, 12.6 g (100 mmol) of B-1, and 2.5 g (10 mmol) of p-toluenesulfonic acid pyridine salt were added to 200 mL of petroleum ether. A water separation apparatus was set up, and the mixture was heated to 90 °C and refluxed for 2 h to separate the water. After cooling to room temperature, 150 mL of water was added to the mixture for liquefaction. The aqueous phase was extracted with 2 × 100 mL of petroleum ether, and the organic phases were combined. The mixture was washed with 3 × 80 mL of water, and the solvent was evaporated at 50 °C under negative pressure to obtain 17.8 g of a light yellow oily liquid C-1.

[0155] Compound C-1 has a purity of 90.6% (including cis and trans) and a yield of 84.8%.

[0156] (2) In a 500ml three-necked flask, add 200mL of tetrahydrofuran and 22.4g (85mmol) of compound D-2, purge with nitrogen more than 3 times, cool to about -85℃, and add 34mL (85mmol, 2.5M) of n-butyllithium dropwise while maintaining the temperature at about -85℃. Keep warm for 1h, then add 17.8g (84.8mmol) of tetrahydrofuran solution of compound C-1 (17.8g C-1 dissolved in 50mL tetrahydrofuran), and keep warm at -85℃ for 2h.

[0157] (3) Dehydration: Naturally heat to -40℃ and add 150mL of saturated ammonium chloride solution. Stir and naturally heat to room temperature. Extract with 3×100mL of n-heptane. Combine the organic phases and wash with 3×100mL of water until neutral. Add 2.1g (8.5mmol) of p-toluenesulfonic acid pyridine salt and react at around 85℃ for 3h.

[0158] (4) Post-treatment: Cool to room temperature, transfer to a separatory funnel, add 3×100mL of water and wash until neutral, then dry with anhydrous sodium sulfate. Spread 15g of 200-300 mesh silica gel, pass the dried product through a column, evaporate the solvent at 50℃ to obtain 28.5g of viscous solid. Add toluene:ethanol = 2:4 for recrystallization, freeze at -30℃ for 3h, filter through a Buchner funnel and dry to obtain 22g of white solid.

[0159] Compound P-2 purity: 99.92%; yield: 74.4%.

[0160] The target product was characterized by mass spectrometry (MS). M+(456): 25 (37%), 26 (13%), 27 (15%), 41 (100%), 43 (11%), 67 (53%), 113 (31%), 127 (39%), 326 (32%), 354 (56%), 371 (13%), 388 (15%), 456 (28%).

[0161] Example 4

[0162] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkene dioxane, the preparation method comprising:

[0163]

[0164] P-3 was obtained by referring to the method in Example 2.

[0165] Compound P-3 purity: 99.9%; yield: 75.1%.

[0166] The target product was characterized by mass spectrometry (MS). M+(324): 25 (33%), 26 (13%), 27 (14%), 41 (100%), 43 (14%), 67 (41%), 113 (29%), 127 (36%), 181 (28%), 222 (48%), 239 (10%), 256 (11%), 324 (23%).

[0167] Example 5

[0168] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkene dioxane, the preparation method comprising:

[0169]

[0170] P-3 was obtained by referring to the method in Example 2.

[0171] Compound P-4 purity: 99.91%; yield: 75.8%.

[0172] The target product was characterized by mass spectrometry (MS). M+(324): 25 (35%), 26 (12%), 27 (13%), 41 (100%), 43 (15%), 67 (41%), 113 (31%), 127 (38%), 222 (48%), 239 (11%), 256 (13%), 324 (28%).

[0173] Example 6

[0174] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkenyl dioxane. The only difference between this method and Example 1 is that in step (1), "the mass of compound A-1 is 15.3g (150mmol) and the mass of B1 is 12.6g (100mmol)", while other operations remain unchanged.

[0175] Compound C-1 has a purity of 78.9% and a yield of 45.3%.

[0176] Example 7

[0177] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkenyl dioxane. The only difference between this method and Example 1 is that in step (1), "the mass of compound A-1 is 10.2 g (150 mmol) and the mass of B1 is 18.9 g (150 mmol)", while other operations remain unchanged.

[0178] Compound C-1 has a purity of 85.1% and a yield of 80.2%.

[0179] Example 8

[0180] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkenyl dioxane. The only difference between this method and Example 1 is that in step (2), n-butyllithium is replaced with an equal amount of diisopropylaminolithium, while other operations remain unchanged.

[0181] Compound P-1 purity: 99.89%; yield: 75%.

[0182] Example 9

[0183] This embodiment provides a method for preparing a liquid crystal compound containing terminal alkenyl dioxane. The only difference between this method and Example 1 is that n-butyllithium in step (2) is replaced with tert-butyllithium in an equal amount, while other operations remain unchanged.

[0184] Compound P-1 purity: 99.88%; yield: 76%.

[0185] For ease of explanation, in the following application examples, the group structures of each component in the liquid crystal composition are represented by the codes listed in Table 1:

[0186] Table 1

[0187]

[0188] Application Example 1

[0189] This application example provides a liquid crystal composition, the composition of which is as follows:

[0190] Component Code Percentage by mass (%) 3CCV 40 5PP1 10 1PP2V 8 3CPPC3 7 3CGPC3 8 3CPUF 9 3CGUF 9 3CPP2V1 4 VDC(V)UF 5

[0191] Application Example 2

[0192] This application example provides a liquid crystal composition, the composition of which is as follows:

[0193] Component Code Percentage by mass (%) 3CCV 40 5PP1 10 1PP2V 8 3CPPC3 7 3CGPC3 8 3CPUF 9 3CGUF 9 3CPP2V1 4 VDC(V)P2V 5

[0194] Application Example 3

[0195] This application example provides a liquid crystal composition, the composition of which is as follows:

[0196]

[0197]

[0198] Application Example 4

[0199] This application example provides a liquid crystal composition, the composition of which is as follows:

[0200]

[0201] Application Example 5

[0202] This application example provides a liquid crystal composition, the composition of which is as follows:

[0203]

[0204] Comparative Application Example 1

[0205] This comparative application example provides a liquid crystal composition, the composition of which is as follows:

[0206]

[0207]

[0208] Comparative Application Example 2

[0209] This comparative application example provides a liquid crystal composition that differs from Application Example 1 only in that the compound with component code VDC(V)UF is replaced in equal amounts with R1 is vinyl, while the other components and their contents remain unchanged.

[0210] Component Code Percentage by mass (%) 3CCV 40 5PP1 10 1PP2V 8 3CPPC3 7 3CGPC3 8 3CPUF 9 3CGUF 9 3CPP2V1 4 VDC(V)PUCF3 5

[0211] Comparative Application Example 3

[0212] This comparative application example provides a liquid crystal composition that differs from Application Example 1 only in that the compound with component code VDC(V)UF is replaced in equal amounts with R1 is vinyl, while the other components and their contents remain unchanged.

[0213]

[0214]

[0215] Test Example 1

[0216] The abbreviations and test methods used in the test projects are shown in Table 2.

[0217] Table 2

[0218]

[0219] The results are shown in Table 3.

[0220] Table 3

[0221]

[0222]

[0223] The applicant declares that this invention illustrates a terminally alkene-containing dioxane liquid crystal compound, its preparation method, and its application through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection and disclosure scope of this invention.

[0224] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0225] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

Claims

1. A liquid crystal compound containing terminal alkenyl dioxane, characterized in that, The compound has the structure shown in Formula I: The R is selected from fluorine, C1-C12 alkyl, fluorinated C1-C12 alkyl, C1-C12 alkoxy, fluorinated C1-C12 alkoxy, C2-C12 alkenyl, C2-C12 alkenyl, fluorinated C2-C6 alkenyl, or fluorinated C2-C6 alkenyl, but not limited to fluorine. Ring A is selected from methyl-substituted, nitrogen-substituted, or unsubstituted rings. Any one of them.

2. The liquid crystal compound containing terminal alkenyl dioxane according to claim 1, characterized in that, The structure of the compound is selected from any one of the following structures:

3. The liquid crystal compound containing terminal alkenyl dioxane according to claim 1 or 2, characterized in that, The compound is selected from any one of the following:

4. The method for preparing the terminally alkene-containing dioxane liquid crystal compound according to any one of claims 1-3, characterized in that, The preparation method includes: (1) React the compound shown in Formula II with the compound shown in Formula III to obtain the compound shown in Formula IV; (2) React the compound shown in Formula IV with the compound shown in Formula V to obtain the compound shown in Formula I; Where X is selected from hydrogen, bromine, or iodine.

5. The method for preparing the terminal olefinic dioxane-containing liquid crystal compound according to claim 4, characterized in that, In step (1), the molar ratio of the compound represented by formula II to the compound represented by formula III is (0.9-1.1):1; Preferably, step (1) is carried out under the conditions of a first organic solvent and a dehydrating agent; Preferably, the molar ratio of the compound represented by Formula III, the first organic solvent, and the dehydrating agent is 1:(3-20):(0.05-1), more preferably 1:(3-10):(0.05-0.2); Preferably, the first organic solvent in step (1) includes any one or a combination of at least two of dichloromethane, dichloroethane, petroleum ether, n-heptane, toluene, or xylene, and more preferably any one or a combination of at least two of dichloromethane, petroleum ether, n-heptane, or toluene.

6. The method for preparing the terminally alkene-containing dioxane liquid crystal compound according to claim 4 or 5, characterized in that, The dehydrating agent includes any one or a combination of at least two of the following: a saturated solution of p-toluenesulfonic acid, p-toluenesulfonic acid pyridinium salt, or hydrochloric acid chloride salt; preferably p-toluenesulfonic acid and / or p-toluenesulfonic acid pyridinium salt. Preferably, the reaction temperature in step (1) is 40-110℃ and the reaction time is 0.5-24h.

7. The method for preparing the terminally alkene-containing dioxane liquid crystal compound according to any one of claims 4-6, characterized in that, Step (2) specifically includes: reacting the compound shown in Formula IV with the compound shown in Formula V under the condition of a second organic solvent to obtain a reaction solution; reacting the reaction solution under the condition of a first organic solvent and a dehydrating agent to obtain the compound shown in Formula I; Preferably, the molar ratio of the compound shown in Formula IV to the compound shown in Formula V is (0.8-2):1, and more preferably (0.9-1.2):1; Preferably, the ratio of the reaction solution, the first organic solvent, and the dehydrating agent is 1:(3-20):(0.05-1), more preferably 1:(3-10):(0.05-0.2); Preferably, the second organic solvent comprises any one or a combination of at least two of diethyl ether, tetrahydrofuran, or 2-methyltetrahydrofuran; Preferably, step (2) is performed under alkaline conditions; Preferably, the alkali is selected from any one or a combination of at least two of n-butyllithium, sec-butyllithium, tert-butyllithium, isopropyl magnesium chloride, isopropyl magnesium chloride, lithium chloride, or diisopropylaminolithium; Preferably, the reaction is carried out in a second organic solvent at a temperature of -100 to 20°C for a time of 0.5 to 24 hours. Preferably, in step (2), the reaction temperature is 20-110°C and the time is 0.5-24h in the presence of the first organic solvent and the dehydrating agent.

8. A liquid crystal composition, characterized in that, The liquid crystal composition comprises any one of the terminal olefinic dioxane liquid crystal compounds according to claims 1-3.

9. The liquid crystal composition according to claim 8, characterized in that, The liquid crystal composition further includes at least one compound of general formula M, at least one compound of general formula A1, and at least one compound of general formula A2; Among them, R M1 and R M2 Each can independently represent -H, a straight-chain or branched alkyl group containing 1-12 carbon atoms, One or more non-adjacent -CH2- atoms in the straight-chain or branched alkyl group containing 1-12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, or -O-CO-. R A1 and R A2 Each independently represents a straight-chain or branched alkyl group containing 1-12 carbon atoms. One or more non-adjacent -CH2- atoms in the straight-chain or branched alkyl group containing 1-12 carbon atoms can be independently replaced by -CH=CH-, -C≡C-, -O-, -CO-, -CO-O-, or -O-CO-, and the straight-chain or branched alkyl group containing 1-12 carbon atoms... One or at least two -H can be independently replaced by -F or -Cl; Z M1 and Z M2 each independently represents a single bond, -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH=CH-, -C≡C-, -CH2CH2- or -(CH2)4-; Z A11 , Z A21 and Z A22 each independently represents a single bond, -CH2CH2-, -CF2CF2-, -CO-O-, -O-CO-, -O-CO-O-, -CH=CH-, -CF=CF-, -CH2O- or -OCH2-; L A11 , L A12 , L A13 , L A21 and L A22 each independently represents -H, alkyl containing 1-3 carbon atoms or halogen; X A1 and X A2 Each can independently represent a halogen, a haloalkyl or haloalkoxy group containing 1-5 carbon atoms, or a haloalkenyl or haloalkenoxy group containing 2-5 carbon atoms. ring ring and ring Each represents independently in, One or at least two of the -CH2- can be replaced by -O-. At most one -H in the halogen can be replaced by a halogen; ring ring ring and ring Each represents independently in, One or more of the -CH2- bonds can be replaced by -O- bonds, and one or more single bonds in a ring can be replaced by double bonds. One or more of the -H can be replaced by -CN, -F or -Cl, and -CH= in one or more of the rings can be replaced by -N=; n M1 n A11 and n A2 Each can independently represent 0, 1, 2, or 3, and when n M1 When = 2 or 3, the ring They can be the same or different, Z M2 They can be the same or different; when n A11 When = 2 or 3, the ring They can be the same or different, Z A11 They can be the same or different; when n A2 When = 2 or 3, the ring They can be the same or different, Z A21 They can be the same or different; n A12 Represents 1 or 2, and when n A12 When = 2, ring They can be the same or different; Preferably, the compound of general formula M accounts for 0.1%-90% of the weight percentage of the liquid crystal composition, the compound of general formula A-1 accounts for 0.1%-80% of the weight percentage of the liquid crystal composition, and the compound of general formula A-2 accounts for 0.1%-80% of the weight percentage of the liquid crystal composition.

10. The use of a terminal olefinic dioxane-containing liquid crystal compound according to any one of claims 1-3 or the liquid crystal composition according to claim 8 or 9 in the preparation of a liquid crystal display device.

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